From 1a1b1669fa4f6912d57cefec664bea18eea8c0b3 Mon Sep 17 00:00:00 2001
From: Fabian Kosmale <fabian.kosmale@qt.io>
Date: Fri, 12 Apr 2024 12:49:18 +0200
Subject: [PATCH] moc: Treat number + characters as Identifier, not Number

While <DIGIT>+<Character> is not a valid identifier by itself in the C++
language, it might become one when using it with the token pasting
operator.

This risks confusing some number literals with suffix as Identifiers,
but those are currently not supported anyway, so this shouldn't break
anything that is currently working.

Fixes: QTBUG-87219
Fixes: QTBUG-124288
Change-Id: If73255cc0e6649bc90c52b1d177aac8ff975ae69
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
(cherry picked from commit 62d02c1d509780eca7d3a4c35ac64a0d475d0fe7)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/tools/moc/preprocessor.cpp   | 13 +++++++++++--
 tests/auto/tools/moc/tst_moc.cpp | 30 ++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/src/tools/moc/preprocessor.cpp b/src/tools/moc/preprocessor.cpp
index f0a61ce6217..11ea8d417e2 100644
--- a/src/tools/moc/preprocessor.cpp
+++ b/src/tools/moc/preprocessor.cpp
@@ -214,7 +214,9 @@ Symbols Preprocessor::tokenize(const QByteArray& input, int lineNum, Preprocesso
                     data -= 2;
                     break;
                 case DIGIT:
-                    while (isAsciiDigit(*data) || *data == '\'')
+                    {
+                    bool hasSeenTokenSeparator = false;;
+                    while (isAsciiDigit(*data) || (hasSeenTokenSeparator = *data == '\''))
                         ++data;
                     if (!*data || *data != '.') {
                         token = INTEGER_LITERAL;
@@ -223,15 +225,22 @@ Symbols Preprocessor::tokenize(const QByteArray& input, int lineNum, Preprocesso
                              || *data == 'b' || *data == 'B')
                             && *lexem == '0') {
                             ++data;
-                            while (isHexDigit(*data) || *data == '\'')
+                            while (isHexDigit(*data) || (hasSeenTokenSeparator = *data == '\''))
                                 ++data;
                         } else if (*data == 'L') // TODO: handle other suffixes
                             ++data;
+                        if (!hasSeenTokenSeparator) {
+                            while (is_ident_char(*data)) {
+                                ++data;
+                                token = IDENTIFIER;
+                            }
+                        }
                         break;
                     }
                     token = FLOATING_LITERAL;
                     ++data;
                     Q_FALLTHROUGH();
+                    }
                 case FLOATING_LITERAL:
                     while (isAsciiDigit(*data) || *data == '\'')
                         ++data;
diff --git a/tests/auto/tools/moc/tst_moc.cpp b/tests/auto/tools/moc/tst_moc.cpp
index a671d92dade..c947da3dd5b 100644
--- a/tests/auto/tools/moc/tst_moc.cpp
+++ b/tests/auto/tools/moc/tst_moc.cpp
@@ -84,6 +84,26 @@ namespace A {
 }
 #endif
 
+
+namespace TokenStartingWithNumber
+{
+Q_NAMESPACE
+
+#define FOR_EACH_ITEM( CALL ) \
+  CALL( EXAMPLE ) \
+  CALL( 123_EXAMPLE ) \
+  CALL( OTHER_EXAMPLE )
+
+enum FooItems
+{
+
+#define ENUM_ITEM(NAME, ...) FOO ## NAME,
+  FOR_EACH_ITEM( ENUM_ITEM )
+};
+
+Q_ENUM_NS(FooItems)
+}
+
 Q_DECLARE_METATYPE(const QMetaObject*);
 
 #define TESTEXPORTMACRO Q_DECL_EXPORT
@@ -851,6 +871,7 @@ private slots:
     void readWriteThroughBindable();
     void invokableCtors();
     void virtualInlineTaggedSlot();
+    void tokenStartingWithNumber();
 
 signals:
     void sigWithUnsignedArg(unsigned foo);
@@ -4667,6 +4688,15 @@ void tst_Moc::virtualInlineTaggedSlot()
     QCOMPARE(method.returnMetaType(), QMetaType::fromType<int>());
 }
 
+void tst_Moc::tokenStartingWithNumber()
+{
+    auto *mo  = &TokenStartingWithNumber::staticMetaObject;
+    int index = mo->indexOfEnumerator("FooItems");
+    QMetaEnum metaEnum = mo->enumerator(index);
+    QVERIFY(metaEnum.isValid());
+    QCOMPARE(metaEnum.keyCount(), 3);
+}
+
 QTEST_MAIN(tst_Moc)
 
 // the generated code must compile with QT_NO_KEYWORDS